This invention relates to surgical stapling assemblies. More particularly, the invention relates to a surgical stapling assembly including a resiliently mounted anvil member and a staple holding assembly for use with an actuator assembly to produce an array of crimped surgical staples in body tissue.
Surgical stapling assemblies have been developed in which a staple holding assembly containing a plurality of surgical staples is pivotally mounted relative to an anvil member. The surgical stapling assembly may be manufactured as an integral part of a surgical stapler, which also includes an actuator assembly, or the stapling assembly may be designed and manufactured as a disposable unit for use in a reusable actuator assembly. Representative of such disposable surgical stapling assemblies and reusable actuator assemblies are those disclosed in copending, commonly assigned, U.S. patent applications Ser. No. 188,691, filed Sept. 29, 1980, now U.S. Pat. No. 4,354,628 and Ser. No. 267,080, filed May 26, 1981 now U.S. Pat. No. 4,383,634. Reference is made to these applications only to show a possible environment for the present invention. The subject matter disclosed in these applications is neither essential for adequate disclosure of the present invention nor essential to support the present claims.
Typically in such surgical stapling assemblies, when the staple holding assembly is pivoted toward the anvil member to clamp tissue inserted therebetween in preparation for stapling, opposing surfaces of the staple holding assembly and the anvil member are spaced apart by a predetermined distance which is fixed by the design of the surgical stapling assembly. This spacing is sometimes referred to herein as the "tissue gap" of the stapling assembly and such stapling assemblies are sometimes referred to herein as being of the "fixed tissue gap type."
Because the tissue gap in this type of stapling assembly is fixed, the operator of an instrument comprising an actuator assembly and the surgical stapling assembly must make sure that he or she does not overload the tissue gap by placing more tissue in the stapling assembly than the tissue gap is designed to contain. Most operators will be unable to clamp the tissue when the stapling assembly is overloaded. But some particularly strong operators may not only ignore the increased resistance to clamping which signals overloading, but may actually be able to clamp the overloaded tissue. In that event, the pressure on the overloaded tissue resulting from the increased clamping force and the fixed tissue gap may be greater than it should be and injury to the overloaded tissue may result.
In view of the foregoing, it is an object of this invention to reduce the chance of injury to the tissue being clamped due to an error in the operator's judgment regarding the correct amount of tissue to be placed in surgical stapling assemblies of the type mentioned above.
It is another object of this invention to reduce the possibility of excessive pressure being applied to tissue in surgical stapling assemblies of the type mentioned above when the stapling assembly is overloaded.